Trademark infringement is another word for the use of a mark by a junior party that is likely to cause consumer confusion with a senior party’s mark. In that situation, a court finding a likelihood of confusion between the marks would also find that the junior party’s mark infringes on the senior party’s mark.

For details about the likelihood of confusion test, please view our guide "When Is There a Likelihood of Confusion Between Two Marks?" The remedies that the prevailing party is entitled to vary based on the court where the dispute is brought.

At the United States Patent & Trademark Office’s Trademark Trial and Appeal Board, an administrative tribunal, the only issue at stake is registration – whether a pending application can be registered (either via an “opposition” proceeding if contested between two parties or via an ex parte appeal of a registration refusal from an Examining Attorney), whether an existing registration should be cancelled (via a “cancellation” proceeding), or whether registration rights should be granted to two users in different geographic areas (a “concurrent use” proceeding).

In federal or state court, the stakes may be higher: the prevailing senior party can each enjoin (prevent) the junior user from using its mark, or receive monetary damages. Registration rights may also be at issue: a federal court can order the USPTO to cancel an existing registration or to deny a pending application.

To the extent that the Trademark Trial and Appeal Board fully vets and decides an issue, a later district court tasked with deciding the same issue will be bound by that outcome, as a 2015 Supreme Court case clarified. B&B Hardware Inc. v. Hargis Indus., Inc., 135 S. Ct. 1293 (2015) (applying issue preclusion).